Unit 10 - Energy and Electrochemistry

Question 1

Electrochemical cells

Answer 1

oxidation occurs at the anode;
reduction occurs at the cathode;
typically loss of mass at the anode and gain of mass at the cathode;
results from spontaneous reactions

Question 2

Iron smelting and thermite reaction

Answer 2

smelting of iron ore in a blast furnace uses a chemical reduction method for iron extraction;
iron (III) oxide reacts with carbon monoxide to form liquid iron and carbon dioixde

Question 3

Difference between electrolytic and voltaic cell - chloralkali process

Answer 3

electrolysis is a non-spontaneous redox reaction that requires external energy (voltage) to drive the chemical transformation;
semi-permeable membrane helps maintain electroneutrality, but prevents mixing of products generated;
concern regarding chlorination of drinking water include residual odour/taste and generation of toxic by-products (trihalomethanes)